config: add yaml/json struct tags

[codeboten]

This will make parsing the configuration easier

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 67.4%. Comparing base (793b970) to head (1aac30d). Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #5433     +/-   ##
=======================================
+ Coverage   66.8%   67.4%   +0.6%     
=======================================
  Files        206     206             
  Lines      13211   13217      +6     
=======================================
+ Hits        8833    8919     +86     
+ Misses      4111    3996    -115     
- Partials     267     302     +35     

Files with missing lines	Coverage Δ
config/config.go	84.3% <100.0%> (+2.0%)	:arrow_up:
config/generated_config.go	53.3% <ø> (+53.3%)	:arrow_up:

[MadVikingGod]

This needs a changelog.

I see this adds additional tags, but I'm not 100% sure how this is used. It doesn't necessarily need to be part of the PR, but could you share an example of how this was used before and how it works now?

[pellared]

Can you add tests that verify that the YAML/JSON files are parsed (thanks to the tags) as expected?

[codeboten]

@MadVikingGod @pellared happy to add some functionality to test it, i didn't want to overstep on this PR https://github.com/open-telemetry/opentelemetry-go-contrib/pull/4826

@carrbs if you're ok with it I can incorporate your work here, or you can pull this change in your PR, it's all the same to me :)

[carrbs]

@MadVikingGod @pellared happy to add some functionality to test it, i didn't want to overstep on this PR #4826

@carrbs if you're ok with it I can incorporate your work here, or you can pull this change in your PR, it's all the same to me :)

I'm good with incorporating here, thanks @codeboten!

[MadVikingGod]

So, what I was hoping for to understand better why this change is necessary was something like: Before:

input := map[string]interface{}
err := json.Unmarshal(rawJson, &input)
config := config{}
err = mapstructure.Decode(input, &config)

But afterwards we have

Some happy path code

While this looks to add direct ways to decode directly into our Config structures, it also means we have to test three different decoders (Mapstructure, Json, and Yaml) and find all the edge cases of each.

[MrAlias]

@MadVikingGod PTAL

[codeboten]

Added test to validate json/yaml parsing is working as expected, also pulled in part of https://github.com/open-telemetry/opentelemetry-go-contrib/pull/4826 for adding a ParseYAML api